The ability of drugs of abuse to affect the behavior of a subject is a well documented phenomena. However, drugs of abuse produce other effects on which there is little information. At the present time there is a paucity of information on the effects of drug on abuse on learning and memory (cognitive function). It is important to determine the possible effects of these drugs on learning and memory to fully understand their pharmacological activity and cost to society. To determine the effects of drugs of abuse on memory and learning, two schedules of reinforcement which have been proposed as models of learning and memory, titrating matching-to-sample and repeated acquisition of response chain, will be studied. Using these schedules, the effects of cocaine, morphine, d- amphetamine, nicotine, caffeine, and a non-abused drug, chlorpromazine will be determined in three species: rat, pigeon, and squirrel monkey. Chlorpromazine, a bahaviorally active non-abused drug, will serve as a control drug and help to determine the specificity of any findings. In addition, since drug abuse in humans is frequently characterized by poly drug use, and the drugs proposed are frequently co-abused, the interactions among these drugs of abuse will be determined by redetermining the dose-response curve for each drug in the presence of selected doses of a second drug. A second goal of this project will be to develop other animal models of learning and memory which will have validity, train rapidly and be adaptable to species with relatively poor visual systems, such as the rat. The first two models to be tried will be a position recall schedule and acquisition of position responding schedule. Once the new methods have been validated, dose-response curves will be determined for each of the 6 drugs listed above, and the interactions among these drugs on the newly developed schedules will be determined as previously described.